Method of effecting sedation, narcosis and muscular relaxation



United States Patent 3,345,259 METHOD OF EFFECTING SEDATION, NARCOSIS AND MUSCULAR RELAXATION Julien Warnant, Neuilly-sur-Seine, Robert Joly, Montmorency, Andr Allais, Les Lilas, and Pierre Girault, Paris, France, assignors to Roussel-UCLAF, Paris, France, a corporation of France No Drawing. Filed Sept. 22, 1965, Ser. No. 489,421 Claims priority, application France, July 21, 1961, 868,569; Oct. 20, 1961, 876,603 Claims. (Cl. 167-52) This application is a continuation-impart of our copending United States patent application Ser. No. 303,698, filed June 19, 1963, now abandoned which application in turn is a division of our United States patent application Ser. No. 209,257, now United States Patent No. 3,156,713.

The present invention relates to a method of effecting sedation, narcosis and muscular relaxation which com prises administering to warm-blooded animals a daily dos-age of from about 105 mg. to about 250 mg. per kilogram of body weight of a compound of the formula wherein R represents a radical selected from the group consisting of hydrogen and the acyl radical of a therapeutically acceptable mineral or organic acid. More particularly the invention relates to the use of alkali metal and alkaline earth metal salts of 3u-phosphato-5fi-androstane-ll-one in eifecting sedation, narcosis and muscular relaxation in warm-blooded animals.

The preparation of 5,8-androstane-3a-ol41=one and its esters with lower alkanoic acids and succinic acid is described in French Patent No. 1,173,938. This French patent describes .a process of preparation of 5/8-androstane-3a-ol-l1-one and its esters by the selective reduction of 518-androstane-3a-ol-11,17-dione and acylation of the 5,8-androstane 3oz 01 -11 one thus obtained with a lower alkanoic acid and particularly acetic acid and with succinic acid. These compounds are disclosed as having interesting physiological and pharamacodynamical properties.

It is an object of the present invention to develop a method of effecting sedation, narcosis and muscular relaxation by administering to warm-blooded animals a safe but effective dosage of a compound of the formula in which R represents a radical selected from the group consisting of hydrogen, the .acyl radical of a therapeutically acceptable mineral acid and the acyl radical of a therapeutically acceptable organic carboxylic acid hav ing from 1 to 12 carbon .atoms.

Another object of the present invention is the development of a method of effecting sedation, narcosis and muscular relaxation by administering to warm-blooded animals from about 1.5 mg. to about 250 mg. per kilo- 3,345,259 Patented Oct. 3 1957 gram of body weight of said warm-blooded animals per day of a phosphate ester of the formula YOO - muscular relaxation when administered to warm-blooded i a solid colorless compound crystallized in needles, soluble animals in daily dosages of from about 1.5 mg. to about 250 mg. per kilogram ofbody Weight of said animals. More particularly, we have found that administration of the phosphoric acid ester of 5(3-and-rostane-3a-0l-1l-one of the formula as well as its alkali metal and alkaline earth metal salts, such as the disodium salt of 3 a-phosphato-5,6-androstanell-one, is particularly effective, especially when administered in the form of the water-soluble salts.

ifl-androstane-3a-ol-ll-one occurs in the form of a solid colorless compound, crystallized in prisms, soluble in acetone, benzene, chloroform, alcohol and ether, slightly soluble in isopropyl ether, insoluble in water. Its melting point determined on the Maquenne block is 131 C., specific rotation [a] =+56.5 (c.=l% in acetone).

The said 5,8 androstane-3a-ol-1l-one can be esterified with .alkanoic acids having from 1 to 12 carbon atoms such as a-cetice acid, or with alkanedioic acids having from 2 to 8 carbon atoms such as succinic acid, or with mineral acids such as phosphoric acid.

3ot-acetoxy-5fl-androstane-ll-one occurs in the form of in alcohol, acetone and methanol, insoluble in water. Its melting point is 130.5 C. and its specific rotation [a] F74- (c.=0.5% in acetone).

31! succinoyloxy SB-androsta'ne-lI-One occurs in the form of a colorless solid compound crystallized in needles, soluble in acetone, benzene, chloroform, alcohol, ether and dilute aqueous alkalis, insoluble in water. Its instantaneous melting point is 126 C. and its specific rotation [a] =+67:l.5 (c.=l% in acetone).

While the above compounds, derivatives 'of compounds of the formula W I (W a) wherein R represents hydrogen, lower alkanoyl or succinoyl are effective in the induction of sedation, narcosis and muscular relaxation according to the invention, they are insoluble in water and must be administered in suspension.

As indicated above the mineral salts of the phosphoric acid ester of fl-andnostane-3u-ol-ll-one possess, in addi tion, the advantage of being soluble in water.

The process of producing the phosphoric acid ester of 5,8-androstane-3a-ol-1l-one, I, and its mineral salts, also part of the invention, is characterized essentially in that 5B-androstane-3a-ol-1l-one, II, is subjected to the action of a functional derivative of phosphoric acid, such as a dibenzyl phosphate halide. 3a-dibenzylphosphato-Sfi-androstane-ll-one, III, is obtained which is subjected to catalytic hydrogenolysis to give 3a-phosphato-5B-androstane-ll-one, I, Whose 3ot-phosphato group is transformed if desired into an alkali metal salt such as the disodium salt, 1V, or an alkaline. earth salt.

In the above description of the process, the Roman numerals refer to the formulas in the flow diagram of In its preferred method of execution, the process above can be characterized by the following points:

(a) The functional derivative of the phosphoric acid used is the dibenzylchlorophosphonate in the form of an ethereal solution and the reaction was conducted at a temperature between about -l5 C. and +5 C.;

(b) The hydrogenolysis of the dibenzylphosphato group is made in the presence of palladized carbon black in ethanolic media at about room temperature;

(c) The salt formation of the 3a-phosphato group is made by neutralization with sodium ethylate.

3a-phosphato 5,8 androstane-ll-one, free acid form, occurs in the form of a colorless solid compound, crystallized inprisms, soluble in alcohol, and dilute aqueous alkalis, insoluble in water, ether, acetone, benzene and chloroform. Its melting point is 258260 C. and its specific rotation [a] =+7O.6 (c.=0.5% in methanol).

The disodium salt of 3a-phosphato-5;3-androstane-11- one is obtained in the form of a hydrate containing 3 molecules of water. It is a solid, crystallized in colorless leaflets, soluble in water and insoluble in organic solvents. Its instantaneous melting point is more than 400 C. and its specific rotation [a] ="-|55.7 (c.=1% in water).

All of these products possess interesting pharmacologioal properties. They possess particularly a neurotropic and depressive action on the central nervous system.

The 5,8-androstane-3m-ol-1l-one and its esters are administered by oral methods, by transcutaneous methods or by rectal methods.

They can be utilized in the form of solutions, injectable suspensions, prepared in ampules or in multiple dose flacons, in the form of tablets or suppositories. The dosology is controlled between about 1.5 mg. and about 250 mg. per day per kilogram of body weight as a function of the method of administration.

Pharmaceutical forms such as solutions or injectable suspension-s, tablets, and suppositories are prepared according to the usual procedures.

The following examples are illustrative of the invention and will enable those skilled in the art to practice the same; they are not to be deemed to limit the invention in any manner. The Roman numerals refer to the formulas in Table I.

EXAMPLE I Preparation 0 3ot-ph0sphat0-5B-androstane-I Lane, I

Step A: Preparation of 3a-dibenzylph0sphat0-5/3-androstwne-JJ-one, HI.9.5 gm. of dibenzylphosphate were introduced into 18 cc. of ether. Then 4.8 gm. of N-chlorosuccinimide were added thereto in small amounts over a period of about 30 minutes under agitation while maintaining the temperature between 25 and 30 C. The agitation was continued for a period of 15 minutes and next the mixture was cooled to +5 C. The precipitate formed was vacuum filtered and washed with ether. The filtrate and the ether wash liquids were combined. Then the solution of dibenzylchlorophosphonate (C H CH O) POCl, so obtained was brought to a Valume of 27 cc. by the addition of ether.

At the same time, 3 gm. of 5 6-androstane-3u-ol-1l-one, II, were dissolved in 30 cc. of anhydrous pyridine. The mixture was subjected to agitation under an atmosphere of nitrogen and cooled to -10 C. Then, in a single amount, 24 cc. of the solution of dibenzylchlorophosphonate obtained as described above were introduced. The agitation was continued for a period of 2 /2 hours at about 5 C. The mixture was allowed to stand overnight at 0 C., then poured into iced water and extracted several times with methylene chloride. The extracts were combined, washed successively with N-hydrochloric acid, with salt water, with a solution of sodium hydroxide and again with salt water. The extracts were dried over sodium sulfate, filtered and the filter washed several times with methylene chloride. The filtrate and the methylene wash liquors were combined and distilled to dryness. Raw compound III was obtained which was purified by chromatography through magnesium silicate with elution with methylene chloride containing 1.6% of methanol. The combined eluates were taken up in isopropyl ether and crystallized. The crystals obtained were vacuum filtered, triturated with cold isopropyl ether and dried under vacuum. 3.8 gm. of 3a-dibenzylphosphato-5 8-androstane-11- one, III, were obtained which could be recrystallized again from isopropyl ether to give a product having a melting point of 82 C. and la specific rotation [a] ='|49.5 (c.=1% in methanol).

The product is soluble in alcohol, ether, acetone, benzene and chloroform and insoluble in water.

Analysis.C H O,-,P; molecular weight=55 0.6. Calculated: C, 71.97%; H, 7.87%; P, 5.62%. Found: C, 72.3%; H, 7.7%; P, 5.8%.

This compound is not described in the literature.

The starting compound was prepared according to the method described in French Patent No. 1,173,938.

Step B: Preparation of 3a-ph0sphato-SB-androstane-I1- one, 1.4 gm. of 3ot-dibenzylphosphato-5,B-androstanell-one, III, were introduced into 40 cc. of ethanol. 0.5 gm. of palladized carbon black containing 10% of palladium was added thereto. The hydrogenation was effected over a period of 5 minutes under agitation and at room temperature. Then the reaction mixture was allowed to stand under an atmosphere of hydrogen and with agitation for a period of about 25 minutes. Next the catalyst was separated and washed with ethanol. The filtrate and the ethanol wash liquors were combined and evaporated to dryness. 2.6 gm. of raw Zia-phosphate- Sfl-andrdstane-ll-one, I, were obtained. 3a-phosphato-5B- androstane-ll-one was purified by solution at elevated temperatures in aqueous acetone, filtration at elevated temperatures, addition of water and crystallization while cold. The purified product had a melting point of 258- 260 C. and a specific rotation [a] =+70.6 (c.=0.5% in methanol).

It is soluble in alcohol and dilute aqueous alkalis; insoluble in water, ether, acetone, benzene and chloroform.

Analysis.C H O P; molecular weight=370.4. Calculated: C, 61.60%;H, 8.43%; P, 8.36%. Found: C, 61.6%; H, 8.4%; P, 8.5%.

This compound is not described in the literature.

Step C: Preparation of disodium salt of 3a-p-hosphatm 5 3-andr0stane-1I-0ne, I V.The disodium salt of 3a-phosphato-Sfi-androstane-ll-one was obtained by action of sodium ethylate on an ethanolic solution of 3a-phosphato- Sfl-androstane-l l-one, I. The disodium salt has a melting point in excess of 400 C. and a specific rotation [a] =+55.7 (c.=l% in water). (The product contained 11% water of solvatation.)

The product is soluble in water, soluble in hot alcohol,

insoluble in ether, acetone, benzene and chloroform.

Analysis.-(After correction for solvatation) 7.05%; P, 7.47%. Found: C, 55.4%; H, 7.1%; P, 7.7%.

This'compound is not described in the literature.

EXAMPLE II Pharmacological studies (a) 5,8-andrstane-3a-0l-1l-one: Study of neuro depressor efiect.Finely ground ,B-androstane-3 a-ol-ll-one was placed in suspension in water and injected by intraperitoneal methods in mice. A sedative effect on the central nervous system was noted which was accentuated with increased dosages and terminated with a narcotic effect which was shown by the loss of the straightening reflex, a test in which an animal lying on its back is no longer able to raise itself.

This narcotic ettect was obtained about minutes after intraperitoneal administration of the medicine and its duration varied with the dose of the medicine injected. Table II below shows the results obtained on different lots of mice.

The sleep obtained by injection of 5B-androstane-3aol-ll-one was particularly calm and the muscular relaxation was very marked. There was no pre-anesthetic agitation. Awakening was very rapid without provoking any agitational phase. In weaker doses than 50 mg./kg., narcosis was not complete. Only a certain somnolence was observed with considerable muscular hypotonia. Weaker doses (10 and mg./kg.) provoked no somnolence. Only a state of quietude appeared with the same muscular hypotonia as that observed with greater dosages. It was noted in particular that the reflexes of the animals and their response to outside stimuli remained in the normal limits.

(b) 3a-ph0sphato-Sfi-androstane-II-one: Study of the neuro-depressor reflect-6a-phosphato-Sfi-androstane-11- one in solution in physiological serum was injected by intravenous methods in different lots of mice at progressively increasing dosages. A profound sedative effect was 7 observed on the central nervous system going to narcosis with increase of the dosage. The narcotic elfect was measured in the same manner as for the 5,8-androstane- 3oc-01-11-On6 by the loss of the straightening reflex. Table III below shows the results obtained with dififerent lots of mice.

. TABLE III Doses injected Duration of sleep in minutes Average mgJkg 35 45 40 45 85 48 min. 200 nag/kg 85 23 5 156 min.

(a) 5,6-androstane-3a-0l-11-ona-Lots of 10 mice of the Rockland strain weighing between 20 and 22 gm. received by intraperitoneal injection an aqueous suspension of 5fi-androstane-3a-ol-l l-one at increasing dosages from 100 mg. to 1 g. per kg. The animals were held under observation for a period of one week. In a general manner, no mortality was observed at a dose of 500 mg./kg. Very much increased dosages of 1 gram per kg. gave, by contrast, a general mortality. The average lethal dose (DL could be evaluated at about 600-700 mg./kg.

b) 3a phosphato 5 ,B-androstane 1-o*ne. 3a-p'hosphato-SB-androstane-ll-one in solution in physiological serum was administered to lots of ten mice of the Rockland strain weighing between 18 and 22 grams by intravenous injection in increasing dosages. The different lots received, respectively, 100, 200 and 500 mg./kg. of 3 a-phosphato-5B-androstane-1l-one. The animals were held under observation for a period of one Week. No mortality was noted'at a dosage of 100 rug/kg.

One death out five animals was observed at a dose of 200 m-g./-kg. and a general mortality for the very large dose of 500' mg./kg. was observed. The average lethal dose (DL -for 3a-phosphato-5B-androstane-ll-one is thus to be evaluated at about 250 mg./kg.

It will be understood that the invention is not limited to the specific modes of execution described above. Particularly, it is evident to one skilled in the art t-hat equivalent techniques such as the use of other therapeutically acceptable esters, may be employed without departing from the spirit of the invention or the scope of the appended claims.

We claim:

1. The method of effecting sedation, narcosis and muscular relaxation by administering to warm-blooded animals from about 1.5 mg. to about 250 mg. per kilogram of body weight per day of a compound of the formula in which R represents a member selected from the group consisting of hydrogen, lower alkanoyl, the monoester of an alkanedioic acid having 2 to 8 carbon atoms, and

wherein Y and Y are selected from the group consisting of hydrogen and alkali metals and, when taken together, divalent alkaline earth metals.

2. The method of effecting sedation, narcosis and muscular relaxation by administering to warm-blooded animals from about 1.5 mg. to about 250 mg. per kilogram 7 of body weight per day of a phosphate ester of the formula O:(\\U YO O \II N wherein Y and Y are selected from the group consisting of hydrogen and alkali metals and, When taken to- 'gether, divalent alkaline earth metals.

3. The method of effecting sedation, narcosis and muscular relaxation by administering to warm-blooded animals from about 1.5 mg. to about 250 mg. per kilogram of body Weight per day of 5,B-androstane-3 x-o1-ll-one.

4. The method of effecting sedation, narcosis and mus- References Cited UNITED STATES PATENTS 3,081,316 3/1963 Sakakibara et a1. 260397.3

FOREIGN PATENTS 1,173,939 11/1958 France.

ALBERT T. MEYERS, Primary Examiner.

L. RANDALL, Assistant Examiner. 

1. THE METHOD OF EFFECTING SEDATION, NARCOSIS AND MUSCULAR RELAXATION BY ADMINISTERING TO WRM-BLOODED ANIMALS FROM ABOUT 1.5 MG. TO ABOUT 25OMG. PER KILOGRAM OF BODY WEIGHT PER DAY OF A COMPOUND OF THE FORMULA 